PDA

View Full Version : Occupant weight and limitations question


Pilot DAR
24th Apr 2011, 02:36
While attempting to remain appropriately non discriminatory, and empathetic, the question none the less can come up;

What do you as a pilot do, when you are presented with a co occupant (passenger/second pilot/instructor/examiner) who appears to have a body weight which exceeds the design capacity of the aircraft seat and seatbel? Though it is not common for a flight manual, or weight and balance, to provide limitations for the occupant weight in a seat, I will offer here the prevailing design standard, which applies to many of the newer aircraft we fly (the older ones are 170 pounds):

Sec. 23.785.

Seats, berths, litters, safety belts, and shoulder harnesses.

[There must be a seat or berth for each occupant that meets the following:]
(a) Each seat/restraint system and the supporting structure must be designed to support occupants weighing at least 215 pounds when subjected to the maximum load factors corresponding to the specified flight and ground load conditions, as defined in the approved operating envelope of the airplane. In addition, these loads must be multiplied by a factor of 1.33 in determining the strength of all fittings and the attachment of--
(1) Each seat to the structure; and
(2) Each safety belt and shoulder harness to the seat or structure.

So if the aircraft has been manufactured so as to be able to safely restrain a 215 pound occupant, and the manufacturer does not provide any information to allow the carriage of a heavier person, what do you do?

You have a stated limitation in a baggage compartment (without being told if that is a C of G/floor loading/restraint limitation) and exceeding that would render your flight not legal. A seat and seatbelt, however, do not seem to have a similarly stated limiting value stated for the pilot's reference.

Just because the C of G and loading of the aircraft could be kept within limitations, would you carry a very heavy person, when you have no information saying that the aircraft is designed to safely support and restrain that person?

Morrisman1
24th Apr 2011, 04:06
just don't go pulling max rate turns with ten-tonne Tessy in the seat.:=

IO540
24th Apr 2011, 06:45
deleted (irrelevant)

Johnm
24th Apr 2011, 06:56
I have a large friend who is quite nimble but over 220 pounds, he fits within the weight and balance criteria of my PA28, but if we were above the weight limit for two in the front (440 pounds) he wouldn't be coming.

Now you come to mention it that might be something to consider with him and an instrcutor in a similar aircraft.....

BackPacker
24th Apr 2011, 09:36
Technically speaking, you've given the answer yourself.

The general W&B limitations of the aircraft, and sometimes of each substation, are a maximum. If you exceed that maximum, you don't fly. Simples.

But the seat strength is a minimum certification limit. It's not a maximum limit. Putting somebody who is heavier than that in the seat (in sofar that's technically possible - these people are not just heavy but take up a lot of space too), unless specifically stated in the POH, is not illegal.

Common sense would dictate that you check the seatbelt can be fastened (or provide an extension) and that all normal movement of, for instance, the flight controls is possible. And since the seats are designed to withstand 215 pounds at 4.4G or so, I wouldn't worry too much about them collapsing during a normal flight.

In the event of a crash though they're not guaranteed the same protection as the other occupants. I think it would be prudent to warn them about that.

And to be honest, I would think that more-or-less the same design criteria apply to cars. And they don't hesitate before getting in a car, do they?